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1.
The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France, the Iberian Peninsula and Morocco) contain autochthonous forms of the brine shrimp Artemia, with parthenogenetic diploid and tetraploid strains coexisting with the bisexual species A. salina. Introduced populations of the American brine shrimp A. franciscana have also been recorded in these Mediterranean environments since the 1980s. Based on brine shrimp cyst samples collected in these countries from 1980 until 2002, we were able to establish the present distribution of autochthonous brine shrimps and of A. franciscana, which is shown to be an expanding invasive species. The results obtained show that A. franciscana is now the dominant Artemia species in Portuguese salterns, along the French Mediterranean coast and in Cadiz bay (Spain). Co-occurrence of autochthonous (parthenogenetic) and American brine shrimp populations was observed in Morocco (Mar Chica) and France (Aigues Mortes), whereas A. franciscana was not found in Italian cyst samples. The results suggest these exotic A. franciscana populations originate as intentional or non-intentional inoculations through aquacultural (hatchery effluents) or pet market activities, and suggest that the native species can be rapidly replaced by the exotic species. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

2.
1. Migratory waterbirds are likely to have a major role in the spread of many exotic aquatic invertebrates by passive dispersal. However, in the field, this has so far only been confirmed in the case of the American brine shrimp Artemia franciscana, which is spreading quickly around the Mediterranean region. 2. We compared experimentally the capacity of A. franciscana and the native brine shrimp Artemia parthenogenetica to disperse via migratory shorebirds. After Artemia resting eggs (cysts) were fed to Redshank Tringa totanus and Dunlin Calidris alpina, we compared the proportion that survived gut passage, their hatchability and their retention time within the gut. We also tested the ability of cysts to stick to the feathers of Black‐tailed Godwit Limosa limosa. 3. The proportion of ingested cysts retrieved from faeces was the same for each Artemia species (8%), and there were no significant differences in retention time (mean 1.2 h and maximum 10 h for A. parthenogenetica, 1.4 and 12 h for A. franciscana) or hatchability (11% versus 14%). The two shorebird species showed similar retention times and retrieval rates, but cysts recovered from Dunlin had a significantly higher hatchability. Only one of the 1000 A. parthenogenetica cysts and three of the 1000 A. franciscana cysts stuck to feathers. 4. These results indicate that both non‐native and native brine shrimps have a similar high capacity for endozoochory via birds, and that the invasiveness of A. franciscana is probably explained by its competitive superiority owing to high fecundity and release from cestode parasitism. Owing to their different migratory behaviour, Redshank and Dunlin are likely to have different roles as brine shrimp vectors. Brine shrimps provide a suitable model for understanding the role of birds in the dispersal of exotic aquatic invertebrates.  相似文献   

3.
ABSTRACT About 1.5-million eared grebes (Podiceps nigricollis), representing half of the North American population, stage on Utah's Great Salt Lake, USA (GSL) during autumn migration to forage on brine shrimp (Artemia franciscana). Indirectly competing with birds for brine shrimp are commercial harvesters who annually collect >1 million kg (dry wt) of shrimp cysts (i.e., hardened eggs), an amount that during some years equals up to half of all brine shrimp cysts produced annually on the GSL. No information was available regarding what impact this commercial harvest was having on eared grebes. We determined daily energy requirements of eared grebes so that regulations governing brine shrimp cyst harvest would better reflect foraging needs of grebes. We measured basal metabolic rate (BMR) of eared grebes from June 2000 to October 2000. Mean BMR of 106 adult and subadult eared grebes was 0.023 kJ/g/hour (SD = 0.004), and mean BMR of 37 juveniles was 0.024 kJ/g/hour (SD = 0.003). Resting and preening metabolic rates were 1.2 times higher than BMR, whereas diving-bout metabolic rate was 1.7 times higher than BMR. Daily energy needs of an average-sized grebe (550 g) during November were 391 kJ. Meeting this energy need requires daily consumption of 24,400 adult brine shrimp. In addition, grebes must consume 2,100–5,200 adult shrimp daily to obtain enough energy reserves to continue their migration to California, USA, and Mexico. Hence, grebes need to consume 26,500–29,600 adult brine shrimp daily while staging on GSL. To achieve this high harvest rate, grebes need adult brine shrimp densities at >380 shrimp/m3during autumn. Commercial harvest of brine shrimp cysts from GSL should be curtailed when cyst densities fall below 20,000 cysts/m3to ensure enough adult brine shrimp for grebes during the subsequent year.  相似文献   

4.
The brine shrimp Artemia is a well known animal extremophile adapted to survive in very harsh hypersaline environments. We compared the small stress proteins artemin and p26, and the chaperone hsc70 in encysted embryos (cysts) of the New World species, A. franciscana and A. persimilis. Cysts of the former, from San Francisco Bay, USA (SFB), were used essentially as a reference for these proteins, while both species were from locations in Chile where they occur in habitats at latitudinal extremes, the Atacama desert and Patagonia. These two species are phylogenetically distant, A. persimilis being closer to the Old World species, whilst A. franciscana is considered younger and undergoing evolutionary expansion. Using western blotting we found all three stress proteins in cysts from these five populations in substantial although variable amounts. The protein profiles revealed by Coomassie staining after electrophoresis (SDS-PAGE) were similar qualitatively, in spite of marked differences in the habitats from which these populations originated, and the long time since they diverged. We interpret these findings as further evidence for the adaptive importance of these three conserved proteins in coping with the variable, but severe stresses these encysted embryos endure.  相似文献   

5.
The chromosomes of three stains of Artemia were studied, a bisexual diploid (A. franciscana, strain GSL), and two parthenogenetic tetraploids from Northern Greece. Routine karyotypes were constructed for the diploid and tetraploid forms, as well as a Giemsa C-banding karyotype of the bisexual form; some data are also presented on the chromosomal C-banding patterns of the parthenogenetic populations. The possible significance of various chromosomal configurations that have been observed, and their relationships to heterochromatin, are discussed.This paper is dedicated to Professor C. Barigozzi for introducing us to Artemia research.Supported by a grant from the Greek Ministry of Agriculture, Request offprints from: Th. Abatzopoulos, Lab. of General Biology, School of Sciences, Aristotelian University, Thessaloniki, 54006, Greece.  相似文献   

6.
The suitability of cysts of the brine shrimp Artemia sp. as a factitious food for the predator Macrolophus pygmaeus Rambur was investigated. The influence of decapsulation time and hydration of the cysts on the performance of the predator were studied in the absence of plant material. A longer time of decapsulation had a positive influence on the development of the predator. Hydration of cysts had a significant impact on nymphal survival when cysts where non‐decapsulated or poorly decapsulated. An experiment in which nymphs were switched from a diet of hydrated cysts to non‐hydrated cysts showed that in the absence of plant material the relative importance of hydrating the cysts decreased with nymphal age. Especially, the first instar and to a lesser extent the second instar appear to be susceptible to water shortage. Effects of prolonged rearing on development and reproduction on brine shrimp cysts from different origins were tested in the presence of plant material. Rearing M. pygmaeus on Artemia sp. (Jingyu Lake) cysts yielded similar survival, development, adult weight and fecundity in the fourth as in the second generation. In contrast, for Artemia franciscana cysts, an increase in nymphal development was notable. Biochemical analyses showed that total amino acid content and the concentration of the different amino acids did not differ among diets and generations. There were, however, differences in total fatty acid content between the different diets and generations and in the concentration of certain fatty acids, indicating that insects fed brine shrimp cysts may show nutritional deficiencies compared to those reared on a diet of Ephestia kuehniella eggs. Our results indicate that decapsulated brine shrimp cysts are an economically viable alternative food source in at least part of the rearing process for M. pygmaeus.  相似文献   

7.
Chromosome numbers in somatic (naupliar) and germinal (adult male) cells of bisexual Artemia populations from the Yucatán Peninsula, SE México (Celestun, CEL; Chuburna, CHUB; Xtampu, XTAM; and Las Coloradas, COL), were compared to those from San Francisco Bay (SFB) and Great Salt Lake (GSL) individuals. Diploid and haploid counts permitted a double-check on results. SFB and GSL samples had low variability in number of chromosomes, with strong modal values of 2n=42 and n=21, typical for A. franciscana. Chromosome counts in the Yucatán brine shrimp samples indicated deviations from the normal 2n=42 karyotype (heteroploidy): COL had chromosome modes of 2n=42 and n=21; CEL of 2n=40 and n=20; CHUB had 2n=44 and n=22; XTAM 2n=48 and n=24. Chromocenter abundance (heterocromatic blocks of highly repetitive DNA) among populations indicated that the North American brine shrimp from SFB and GSL had a mean of 15.9 and 15.1 chromocenters, respectively. From the Yucatán brine shrimp, COL had a variable number of chromocenters, ranging from 5 to 15 with a mean value of 9.9. The other three Artemia populations had much fewer chromocenters (CEL 1–3, XTAM 1–8, and CHUB 1–4). Heteromorphic sex chromosomes were apparent in some Yucatán karyotypes preparations. The haplotype condition in the Yucatán Artemia populations, though similar to that found in some Italian A. salina populations, is reported for the first time in New World Artemia. This cytological characteristic of the Yucatán Artemia, in conjunction with their morphological and allozyme differentiation, could provide new insight for the role of chromosome rearrangements in the evolutionary process of Artemia in the New World.  相似文献   

8.
Stappen  Gilbert Van  Sui  Liying  Xin  Naihong  Sorgeloos  Patrick 《Hydrobiologia》2003,500(1-3):179-192
The brine shrimp Artemia was discovered in a number of saline lakes on the Qinghai-Tibet Plateau, widely diverging in chemical composition. Several lakes were athalassohaline, with relatively high amounts of trace elements. Common environmental factors are their high altitude (exceeding 4500 m) and the low average annual temperatures. A number of Artemia populations in this area were analysed to assess their preference for low temperatures and an athalassohaline medium. Furthermore, their characteristics were compared with Artemia tibetiana, the species recently described for one lake in this area. All samples contained a variable mixture of parthenogenetic and bisexual individuals. A cross-breeding test of the sample from Jingyu Lake showed cross-fertility both with A. tibetiana and A. sinica. All populations showed similarities to A. tibetiana: a large cyst diameter and naupliar length, high HUFA content and a high tolerance to low temperatures, as compared to the control A. franciscana samples. These can thus be considered as recurrent characteristics of the populations from the high-altitude low-temperature environment on the Qinghai-Tibet Plateau, although further research is needed to identify their exact species status.  相似文献   

9.
Autoinducer 2 (AI-2) quorum sensing was shown before to regulate the virulence of Vibrio harveyi towards the brine shrimp Artemia franciscana. In this study, several different pathogenic V. harveyi, Vibrio campbellii, and Vibrio parahaemolyticus isolates were shown to produce AI-2. Furthermore, disruption of AI-2 quorum sensing by a natural and a synthetic brominated furanone protected gnotobiotic Artemia from the pathogenic isolates in in vivo challenge tests.  相似文献   

10.
W.D. Emmerson 《Hydrobiologia》2001,466(1-3):221-229
Encysted embryos (cysts) of the brine shrimp, Artemia provide an excellent model system for the study of biochemical adaptation to environmental extremes. Here, we describe an experiment in which cysts of A. franciscana from the San Francisco Bay (SFB), California, U.S.A., were inoculated into experimental ponds in the Mekong Delta region of Vietnam where water temperatures are much higher than the SFB. Cysts produced in each of three successive growing seasons (1996–1998) were collected and examined in the laboratory for resistance to high temperature and relative contents of three stress proteins (Hsp-70, artemin and p26). Thermal adaptation took place rapidly, during the first growing season. The increase in thermal tolerance was reflected in an overall increase in stress protein content, compared to SFB cysts used for the initial inoculation. Also examined were cysts of A. tibetiana collected from a lake on the high plateau of Tibet, PR China, almost 4.5 km above sea level. These cysts were very sensitive to high temperatures, and contained much lower levels of all stress proteins examined, compared to A. franciscana cysts from SFB and Vietnam. Cysts of A. sinica, collected from a hypersaline lake in Inner Mongolia, PR China, were examined in the same fashion and found to be similar to SFB cysts in terms of thermal resistance and stress protein content. The harsh environments in which Artemia are found, and the great diversity of its habitats, world-wide, provide excellent opportunities to relate the ecological setting of an organism to the underlying physiological and biochemical processes enabling its survival.  相似文献   

11.
The identification of the environmental conditions inducing different ecophysiological responses in the different strains and populations of the brine shrimp Artemia should improve the understanding of their biogeographic distribution. Nauplii from two Argentinean brine shrimp populations, Artemia persimilis from Salinas Grandes de Hidalgo (province of La Pampa) and Artemia franciscana from Laguna Mar Chiquita (province of Cordoba), were grown up until adulthood at different salinities (30, 60, 90, 120 gL−1) and temperatures (12, 21, 28°C). The aim was to assess the effects of these different conditions on prereproductive life span and reproductive traits. Results evidenced that at 21 and 28°C, at any salinity, A. franciscana from Laguna Mar Chiquita attained higher survival and fecundity, after a shorter prereproductive period, than A. persimilis from Salinas Grandes de Hidalgo. These data support that A. franciscana, considered a superspecies, exhibits higher phenotypic plasticity than A. persimilis, and that A. persimilis is better adapted to lower temperatures than A. franciscana. These differences in temperature and salinity tolerance could explain the present distribution of these two species in the South Cone in South America. Handling Editor: J. Melack  相似文献   

12.
A highly hydrophilic, glutamate-rich protein was identified in the aqueous phenol extract from the cytosolic fraction of brine shrimp (Artemia franciscana) diapausing cysts and termed Artemia phenol soluble protein (PSP). Mass spectrometric analysis revealed the presence of many protein peaks around m/z 11,000, separated by 129 atomic mass units; this value corresponds to that of glutamate, which is strongly suggestive of heterogeneous polyglutamylation. Polyglutamylation has long been known as the functionally important post-translational modification of tubulins, which carry poly(l-glutamic acid) chains of heterogeneous length branching off from the main chain at the γ-carboxy groups of a few specific glutamate residues. In Artemia PSP, however, Edman degradation of enzymatic peptides revealed that at least 13, and presumably 16, glutamate residues were modified by the attachment of a single l-glutamate, representing a hitherto undescribed type of post-translational modification: namely, multiple γ-glutamylation or the addition of a large number of glutamate residues along the polypeptide chain. Although biological significance of PSP and its modification is yet to be established, suppression of in vitro thermal aggregation of lactate dehydrogenase by glutamylated PSP was observed.  相似文献   

13.
Artemia cysts collected from inoculation experiments in Cam Ranh salterns are evaluated for their potential use in aquaculture. Cyst biometrics, hatching quality, naupliar fatty acid profile and naupliar growth were measured and compared to reference Artemia strains. Cyst characteristics reveal that the parthenogenetic strain (PR China) used in inoculations, was eliminated from the environment and that the remaining brine shrimp are likely to be composed of Macau and Great Salt Lake Artemia strains, and of their cross-breds. Differences in cyst diapause deactivation characteristics between Macau and Great Salt Lake Artemia may have resulted in the disappearance of Macau Artemia during the rainy season and the persistence of Great Salt Lake Artemia during the following dry season.  相似文献   

14.
We report on the construction of sex-specific linkage maps, the identification of sex-linked markers and the genome size estimation for the brine shrimp Artemia franciscana. Overall, from the analysis of 433 AFLP markers segregating in a 112 full-sib family we identified 21 male and 22 female linkage groups (2n = 42), covering 1,041 and 1,313 cM respectively. Fifteen putatively homologous linkage groups, including the sex linkage groups, were identified between the female and male linkage map. Eight sex-linked AFLP marker alleles were inherited from the female parent, supporting the hypothesis of a WZ–ZZ sex-determining system. The haploid Artemia genome size was estimated to 0.93 Gb by flow cytometry. The produced Artemia linkage maps provide the basis for further fine mapping and exploring of the sex-determining region and are a possible marker resource for mapping genomic loci underlying phenotypic differences among Artemia species.  相似文献   

15.
Cysts of the brine shrimp Artemia franciscana are harvested from the Great Salt Lake (GSL) and San Francisco Bay (SFB) saltworks in the USA, and marketed worldwide to provide live food for aquaculture. This species has become invasive across several countries. We investigated (1) if the introduced populations in the Mediterranean region could have originated from these USA populations, (2) how the genetic diversity of Mediterranean compares to that at GSL and SFB, and (3) if genetic patterns in the Mediterranean can shed light on colonization routes. We sequenced a fragment of the cytochrome c oxidase subunit I and screened microsatellites loci from Mediterranean populations and the two putative USA sources. Haplotypes from Mediterranean populations were identical or closely related to those from SFB and GSL, and not related to other available American populations. Microsatellite analyses showed a reduced population diversity for most Mediterranean populations suggesting bottleneck effects, but few populations were showing similar or higher genetic diversity than native ones, which are likely to be admixed from both GSL and SFB because of multiple introductions. Results suggest natural dispersal, potentially via flamingos, between two Spanish populations. Our analyses show that all invaded populations could have originated from those commercialized USA populations.  相似文献   

16.
The generalist predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) was reared on Ephestia kuehniella Zeller eggs (Lepidoptera: Pyralidae), decapsulated dry cysts of the brine shrimp Artemia franciscana Kellogg (Anostraca: Artemiidae), and on meridic artificial diets (composed of honey, sucrose, tryptone, yeast extract, and egg yolk) supplemented with pupal hemolymph of the Chinese oak silkworm Antheraea pernyi (Guérin-Méneville) (Lepidoptera: Saturniidae) (AD1), with E. kuehniella eggs (AD2) or with A. franciscana cysts (AD3). Development, reproduction and predation capacity of the predatory mites were assessed in the first (G1) and sixth generation (G6) of rearing on the different diets. Immature survival rates in G1 were similar on all diets (96.8–100 %). After six generations, however, survival of A. swirskii was significantly reduced on all diets except on A. franciscana cysts. Oviposition rates did not differ between generations when females were fed on E. kuehniella, AD2 or AD3. The total number of deposited eggs was similar among diets except in G6 where the females fed on A. franciscana cysts produced more eggs than those maintained on E. kuehniella eggs. On most diets the intrinsic rates of increase in G1 were superior to those in G6, except for predators supplied with A. franciscana cysts where no differences were observed among generations. Female mites did not lose their capacity to kill first instar Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) after six generations on the different diets, but predation rates in G6 on E. kuehniella were lower than in G1. In conclusion, the different factitious and artificial diets tested in the present study supported the development and reproduction of A. swirskii for a single generation but fitness losses occurred to a varying degree after several generations on E. kuehniella eggs or the artificial diets. Artificial diet enriched with A. franciscana cysts yielded better results than the other artificial diets. Amblyseius swirskii performed best on decapsulated Artemia cysts indicating their potential for use in the mass production of the predator or to sustain its populations in the crop after release.  相似文献   

17.

Background

Artemia (Crustacea, Anostraca), also known as brine shrimp, are typical inhabitants of extreme environments. These hypersaline environments vary considerably in their physicochemical composition, and even their climatic conditions and elevation. Several thalassohaline (marine) environments along the Colombian Caribbean coast were surveyed in order to contribute to the knowledge of brine shrimp biotopes in South America by determining some vital biological and physicochemical parameters for Artemia survival. Additionally, cyst quality tests, biometrical and essential fatty acids analysis were performed to evaluate the economic viability of some of these strains for the aquaculture industry.

Results

In addition to the three locations (Galerazamba, Manaure, and Pozos Colorados) reported in the literature three decades ago in the Colombian Caribbean, six new locations were registered (Salina Cero, Kangaru, Tayrona, Bahía Hondita, Warrego and Pusheo). All habitats sampled showed that chloride was the prevailing anion, as expected, because of their thalassohaline origin. There were significant differences in cyst diameter grouping strains in the following manner according to this parameter: 1) San Francisco Bay (SFB-Control, USA), 2) Galerazamba and Tayrona, 3) Kangarú, 4) Manaure, and 5) Salina Cero and Pozos Colorados. Chorion thickness values were smaller in Tayrona, followed by Salina Cero, Galerazamba, Manaure, SFB, Kangarú and Pozos Colorados. There were significant differences in naupliar size, grouping strains as follows (smallest to largest): 1) Galerazamba, 2) Manaure, 3) SFB, Kangarú, and Salina Cero, 4) Pozos Colorados, and 5) Tayrona. Overall, cyst quality analysis conducted on samples from Manaure, Galerazamba, and Salina Cero revealed that all sites exhibited a relatively high number of cysts.g-1. Essential fatty acids (EFA) analysis performed on nauplii from cyst samples from Manaure, Galerazamba, Salina Cero and Tayrona revealed that cysts from all sites exhibited high arachidonic acid:20:4(n-6) (ArA) and eicosapentaenoic acid: 20:5(n-3) (EPA) levels comparable to the control sample (SFB). In contrast, most cysts collected (including SFB) at different locations, and during different months, presented low docosahexaenoic acid: 22:6(n-3) (DHA) levels (Manaure was the only exception with high DHA levels). Some variations in EPA and ArA levels were observed in all sites, contrasting with the much lower DHA levels which remained constant for all locations, except for Manaure which exhibited variable DHA levels. DHA/EPA ratio was overall very low for all sites compared to SFB cysts. All strains had a low DHA/ArA, but a high EPA/ArA ratio, including the control.

Conclusion

The Colombian A. franciscana habitats analyzed were determined to be thalassohaline, and suitable for A. franciscana development. EFA profiles demonstrated that Tayrona, Galerazamba, Manaure and Salina Cero strains are suitable food for marine fish and crustacean culture because of their high EPA/ArA ratio, but might have to be fortified with DHA rich emulsions depending on the nutritional requirements of the species to be cultured, because of their overall low DHA content. The relatively small nauplii are appropriate for marine larvaeculture. In contrast, the strains from Tayrona, Kangarú, Salina Cero, and Pozos Colorados may be of use but limited to Artemia small biomass production quantities, because of the small surface area of their respective locations; Artemia could be exploited at these locations for local aquaculture applications. In general, cyst quality evaluation for Manaure, Salina Cero and Galerazamba cysts revealed that cysts from these three locations could improve their quality by concentrating efforts on cyst processing techniques. Finally, most locations had great A. franciscana production potential and require different degrees of water quality and/or infrastructure management.  相似文献   

18.
The brine shrimp Artemia (Crustacea, Branchiopoda), a paradigmatic inhabitant of hypersaline lakes, has molecular features to survive under stressful conditions, such as the p26 heat shock protein. We report the RFLP fingerprinting pattern (four restriction enzymes) of a 217 bp fragment of exon2 of the Hsp26 gene in six Artemia franciscana and four Artemia persimilis populations, the most genetically divergent Artemia species co-occurring in latitudinal extremes of Chile. The species-specific RFLP pattern observed is a simple and cost-effective single-locus tool for species delimitation and experimental testing the habitat-induced isolation barrier between them.  相似文献   

19.
20.
Late embryogenesis abundant (LEA) proteins are a large group of anhydrobiosis-associated intrinsically disordered proteins, which are commonly found in plants and some animals. The brine shrimp Artemia franciscana is the only known animal that expresses LEA proteins from three, and not only one, different groups in its anhydrobiotic life stage. The reason for the higher complexity in the A. franciscana LEA proteome (LEAome), compared with other anhydrobiotic animals, remains mostly unknown. To address this issue, we have employed a suite of bioinformatics tools to evaluate the disorder status of the Artemia LEAome and to analyze the roles of intrinsic disorder in functioning of brine shrimp LEA proteins. We show here that A. franciscana LEA proteins from different groups are more similar to each other than one originally expected, while functional differences among members of group three are possibly larger than commonly anticipated. Our data show that although these proteins are characterized by a large variety of forms and possible functions, as a general strategy, A. franciscana utilizes glassy matrix forming LEAs concurrently with proteins that more readily interact with binding partners. It is likely that the function(s) of both types, the matrix-forming and partner-binding LEA proteins, are regulated by changing water availability during desiccation.  相似文献   

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